Wolfe Chapter 14 Review Questions - Olfaction

Front 1

How is the olfactory epithelium involved in odor perception?

Back 1

The olfactory epithelium contains three types of cells that allow it to detect odorants in the inspired air.

Front 2

Name and describe the three cells found in the epithelium.

Back 2

The three cells found in the epithelium are: 1) supporting cells, which perform metabolic and physical supportive functions; 2) basal cells, which are precursor cells to olfactory sensory neurons; and 3) olfactory sensory neurons, which possess cilia that contain the receptor sites for odorant molecules.

Front 3

Explain the role of the olfactory bulbs in odor perception.

Back 3

The olfactory bulbs are the first sites in the brain where olfactory information is processed.

Front 4

How is the limbic system involved in odor perception?

Back 4

The limbic system is involved in many aspects of emotion and memory. It has direct and strong connections to the olfactory system, which explains the strong relationship between emotion, memory, and odor perception.

Front 5

What kinds of sensations are mediated by the trigeminal nerve?

Back 5

The trigeminal nerve transmits information about the “feeling” dimension of smell. For instance, menthol feels cool, and ammonia feels burning.

Front 6

What does the shape-pattern theory contend?

Back 6

The shape-pattern theory contends that odorant molecules and olfactory receptors have specific shapes, and that an odorant will be detected by a specific olfactory receptor to the extent that the odorants’ molecules fit into the olfactory receptor like a key fits into a lock.

Front 7

What does the vibration theory contend?

Back 7

The vibration theory contends that there is a different vibration frequency for every perceived smell, and that molecules that produce the same vibration frequencies will produce the same smell.

Front 8

Provide one piece of evidence in favor of the shape-pattern theory of olfactory perception.

Back 8

One piece of evidence in favor of this theory is the study of stereoisomers. Stereoisomers are molecules that are mirror-image rotations of one another, and although containing the same atoms, they can smell completely different. According to the shape-pattern theory, this difference arises because the rotated molecules do not fit the same receptors.

Front 9

What two kinds of processes are thought to be involved in the perception of odor mixtures?

Back 9

The two processes involved in the perception of odor mixtures are analysis and synthesis.

Front 10

What is binaral rivalry?

Back 10

When one scent is presented to the left nostril and another scent is presented to the right nostril at the same time, they compete with each other to be perceived. Only one scent at a time is perceived rather than a combination of the two scents, and which scent is perceived switches back and forth over time.

Front 11

Provide one example of the difference in processing between olfaction and vision.

Back 11

Odor imagery is not possible within the realm of olfaction. It is not possible to imagine a particular smell very clearly. However, it is possible to imagine a visual image very clearly and easily.

Front 12

Explain whether odor recognition is durable over time or not.

Back 12

Odor recognition is durable over time. That is, when exposed to a particular odor once, its recognition is relatively stable over the course of one day, a week, or even a year.

Front 13

What is the “tip-of-the-nose” phenomenon?

Back 13

The “tip-of-the-nose” phenomenon is the inability to name an odorant, even though it is very familiar. The phenomenon is evidence that language and olfaction are deeply disconnected.

Front 14

Why is cross-adaptation presumed to occur?

Back 14

Cross-adaptation is the successive reduction in detection of an odorant following exposure to another odorant. It is presumed to occur because the two odorants share one or more olfactory receptors for their transduction, but the order of odorant presentation also plays a role.

Front 15

What is cognitive habituation?

Back 15

Cognitive habituation is the psychological process by which, after long-term exposure to an odorant, one is no longer able to detect that odorant or has very diminished detection ability.

Front 16

What is odor hedonics?

Back 16

Odor hedonics is the liking dimension of odor perception. It is typically measured with scales pertaining to an odorant’s perceived pleasantness, familiarity, and intensity.

Front 17

Provide evidence that hedonic responses to odors are learned.

Back 17

Evidence that hedonic responses are learned comes from cross-cultural data, where people acquire a taste for various foods that are considered “disgusting” by other cultures.

Front 18

Provide evidence that hedonic responses to odors are innate.

Back 18

Evidence that hedonic responses to odors are innate come from the idea that there is a cross-cultural agreement for some hedonic responses to common everyday smells, labeling them as either “good” or “bad.”

Front 19

What is a learned taste aversion?

Back 19

A learned taste aversion is the avoidance of a novel flavor after it has been paired with gastric illness. It is the smell, not the taste, of the substance that is the key for learned aversion response in humans.

Front 20

Why do odors have a reputation of being the “best cues” for memory?

Back 20

Odors have a reputation of being the “best cues” for memory because very often a smell elicits a strong emotion or memory that other modalities, such as vision or audition, do not.

Front 21

Explain the role of the orbitofrontal cortex in odor perception.

Back 21

The orbitofrontal cortex is responsible for processing olfaction. It is also the area of the brain that is critical for assigning affective value to stimuli (i.e., liking or disliking), and for determining hedonic meaning.

Front 22

What is a pheromone?

Back 22

A pheromone is a chemical emitted by one member of a species that triggers a physiological or behavioral response in another member of the same species. Pheromones do not necessarily have any smell.